I've never had the opportunity to fly into a controlled airport with parallel runways, so I've never actually faced the situation. But, in the interest of being ahead of it, when would it be prudent to switch to ground frequency with this clearance (assume I just landed)?

"N12345, right on E, cross 27 R, contact ground .9"

Should I call ground (or switch frequency, so I no longer hear the tower) before or after crossing 27 R? My assumption would be immediately, as there's no "then" or "after crossing" or similar, but somehow that feels wrong. I suppose normally it doesn't really matter, but in the case of someone (which includes me, everyone makes mistakes) doing something wrong, where would they call me as I'm about to cross 27 R?

If you landed 27L and were told to cross 27R and contact ground, I would remain with the tower until after crossing 27R. More than likely 27R is also an active runway that the tower is controlling in which case you don't want to be switching to ground before crossing that runway. If he wanted you to go to ground right away, he would have simply said:

I'm not a tower controller but I have been a radar controller for 11 years, so FWIW if I were to say what you said then it means I want you to change to ground now. If I say "contact tower at ALPHA" or "leaving 3000 contact tower" it means stay on my frequency until do what I said. I've never just said "contact..." without restrictions when I wanted the plane to do something before switching freq.

If you landed 27L and were told to cross 27R and contact ground, I would remain with the tower until after crossing 27R. More than likely 27R is also an active runway that the tower is controlling in which case you don't want to be switching to ground before crossing that runway.

I'm not a tower controller but I have been a radar controller for 11 years, so FWIW if I were to say what you said then it means I want you to change to ground now. If I say "contact tower at ALPHA" or "leaving 3000 contact tower" it means stay on my frequency until do what I said. I've never just said "contact..." without restrictions when I wanted the plane to do something before switching freq.

These are exactly the two conflicting ideas in my head and I'm leaning towards the latter. I recently saw a YouTube video though where the guy did the former, which prompted me to think about it in the first place. Let's say someone was given a line-up-and-wait on 27 R, but instead of waiting they started their takeoff roll. I wouldn't know since I wasn't listening on that frequency, would you yell out on both frequencies? Or would you simply never say 'cross 27 R, contact ground' if 27 R was in use?

In my experience if runway 27R was not an active runway, it would not be under the control of the tower controller. Instead it would be under the control of the ground controller and be treated as a taxiway. You would have then been told something like this:

"N12345 turn right on E and contact ground .9"

If 27R is an active runway, then 27R would be under the tower controller. If there's no landing or departing traffic on 27R at the time, he can tell you:

"right on E, cross 27R, contact ground .9"

If I were the tower controller I would added a little more to that line to avoid confusion:

"N12345, right on E, cross 27R and contact ground .9 on the other side"

So for me, if the tower guy tells me what you said, I would take that as contact ground after crossing 27R. If the tower guy tells you to cross a runway, then he has control of that runway, not the ground controller. If another aircraft were told to line up and wait but instead started their takeoff roll, then I don't think the tower guy would want you on the ground freq if he needed to suddenly stop you short of 27R.

But then, of course, if there's any doubt, you could always just ask if you should "stay with him" or "switch to ground now".

I would expect the pilot to contact ground immediately when I say "contact ground," regardless of any other instructions. If I want a pilot to remain on my tower frequency until a certain point, then I will say "cross runway xx, then contact ground .x" Or I will just say "remain this frequency," and then issue a frequency change when I want the pilot to change.

The tower controller in this example has introduced ambiguity into the situation which leads to assumptions of active/inactive runways, or who controls runways, but I believe his intent was for the pilot to contact ground immediately. I don't believe ambiguity has a place in ATC communications and would not recommend using the type of phraseology described in this example. At least that's the way I have worked and trained for the past 30 years at airports with parallel runways.

Yes, I agree, the original instruction as suggested by Roe is amibiguous; it's not exactly clear when the pilot should contact ground. It could be taken either way. If I were in that situation, I'd ask to make sure I switched to ground when he wanted me to.

If you landed 27L and were told to cross 27R and contact ground, I would remain with the tower until after crossing 27R. More than likely 27R is also an active runway that the tower is controlling in which case you don't want to be switching to ground before crossing that runway. If he wanted you to go to ground right away, he would have simply said:

"N12345, right on E, contact ground .9"

That's what I would do if that happened to me.

Ron

The problem now, which adds even more to the ambiguity, is that regardless of if the runway is active or not, you need an explicit crossing clearance to cross the runway. That change was made to the .65 roughly 2 - 3 years ago to deal with runway incursions from being told "taxi to runway xx", which gave the aircraft clearance to cross any non-active runway on their way to the assigned runway. So this could have been active or inactive. doesn't take away the ambiguity, though.

its been many many many moons the last time i was a tower flower , but like the other controllers said the example you gave you would switch to ground right away. if the controller wants you to stay on their freq till you crossed the other rwy it should be with the clrn to cross the rwy. i see no ambiguity in any of this in the new rule or the old rule.

I would taxi via Echo across RWY 27R and contact ground on the other side of the runway I cross. While almost completely unlikely, in the event something happened that caused the runway to suddenly become occupied before I cross it -- say a deer runs out onto 27L in front of a landing Cessna which then asks for and is cleared to land on RWY 27R, which I'm about to cross, or let's say a crazy man busts the perimeter fence and drives onto the runway -- this helps me judge whether or not I should still cross the runway. Without an explicit instruction to contact the ground controller right then and there, I would wait. Just because I'm told to cross an active runway doesn't mean I should stop paying attention to what's going on. By switching to the ground control frequency, you're no longer actively engaged with what's going on on the runway you're about to cross. Anything can happen.

I would taxi via Echo across RWY 27R and contact ground on the other side of the runway I cross. While almost completely unlikely, in the event something happened that caused the runway to suddenly become occupied before I cross it -- say a deer runs out onto 27L in front of a landing Cessna which then asks for and is cleared to land on RWY 27R, which I'm about to cross, or let's say a crazy man busts the perimeter fence and drives onto the runway -- this helps me judge whether or not I should still cross the runway. Without an explicit instruction to contact the ground controller right then and there, I would wait. Just because I'm told to cross an active runway doesn't mean I should stop paying attention to what's going on. By switching to the ground control frequency, you're no longer actively engaged with what's going on on the runway you're about to cross. Anything can happen.

AHHHHHH or how about this "N123 unable go around traffic crossing the rwy" but thats the difference between book ATC and real ATC. OH and do you think that if some nut bag did bust the fence that you would still run operation to the airport..................................NOT.

AHHHHHH or how about this "N123 unable go around traffic crossing the rwy" but thats the difference between book ATC and real ATC. OH and do you think that if some nut bag did bust the fence that you would still run operation to the airport..................................NOT.

I'm not even going to start on this...

Anyway, back on topic. Now that I think about this again, I would stay on tower frequency until clear of the runway, unless explicitly told to contact ground, per ronr530's case. If the runway is active, Tower still has control over the active runway and taxiways between those runways, whereas Ground would have control over it if the runway is not active.

In this case, StuSEL is also right that the pilot would be disengaged with what is going on on the runway, as he would be on the frequency of the controller who does not control the active. With that, I'd say that with the call above, stay on Tower's frequency until after crossing, then contact Ground.

It is also possible that Tower may have some additional instructions for the pilot after giving this call, and since they control the active and that taxiway, it would be best to be available to receive them.